package org.smart4j.framework.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileFilter;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * Created by Wangminze on 2016/12/11.
 * Description: 类操作工具类
 */
public class ClassUtil {

    private static final Logger LOGGER = LoggerFactory.getLogger(ClassUtil.class);

    /**
     * author: Wangminze
     * date: 2016/12/11
     * description:获取类加载器
     * @return
     */
    public static ClassLoader getClassLoader(){
        //DONE
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * author: Wangminze
     * date: 2016/12/11
     * description:加载器
     * @param className
     * @param isInitialized
     * @return
     */
    public static Class<?> loadClass(String className,boolean isInitialized){
        //DONE
        Class<?> cls;
        try {
            cls = Class.forName(className, isInitialized, getClassLoader());
        }catch (ClassNotFoundException e){
            LOGGER.error("Load class failure", e);
            throw new RuntimeException(e);
        }
        return cls;
    }

    /**
     * author: Wangminze
     * date: 2016/12/11
     * description:获取指定包下的所有类
     * @param packageName
     * @return
     */
    public static Set<Class<?>> getClassSet(String packageName){
        //TODO

        Set<Class<?>> classSet = new HashSet<Class<?>>();
        try {
            Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".","/"));
            while (urls.hasMoreElements()){
                URL url = urls.nextElement();
                if( url != null ){
                    //协议
                    String protocal = url.getProtocol();
                    if ( "file".equals(protocal) ){
                        String packagePath = url.getPath().replaceAll("%20"," ");
                        addClass(classSet, packagePath, packageName);
                    }else if ( "jar".equals(protocal) ){
                        JarURLConnection jarURLConnection = (JarURLConnection) url.openConnection();
                        if( jarURLConnection != null ){
                            JarFile jarFile = jarURLConnection.getJarFile();
                            if ( jarFile != null ){
                                Enumeration<JarEntry> jarEntries = jarFile.entries();
                                while(jarEntries.hasMoreElements()){
                                    JarEntry jarEntry = jarEntries.nextElement();
                                    String jarEntryName = jarEntry.getName();
                                    if( jarEntryName.endsWith(".class")){
                                        String className = jarEntryName.substring(0
                                                , jarEntryName.lastIndexOf(".")).replaceAll("/", ".");
                                        doAddClass(classSet, className);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }catch (Exception e){
            LOGGER.error("Get class set failure", e);
            throw new RuntimeException(e);
        }
        return classSet;
    }

    public static void addClass(Set<Class<?>> classSet, String packagePath, String packageName){
        File[] files = new File(packagePath).listFiles(new FileFilter(){
            @Override
            public boolean accept(File file) {
                return ( file.isFile() && file.getName().endsWith(".class")) || file.isDirectory();
            }
        });

        for (File file: files){
            String fileName = file.getName();
            if (file.isFile()){
                String className = fileName.substring(0, fileName.lastIndexOf("."));
                if(StringUtil.isNotEmpty(packageName)){
                    className = packageName + "." + className;
                }
                doAddClass(classSet, className);
            }else{
                String subPackagePath = fileName;
                if(StringUtil.isNotEmpty( packageName)){
                    subPackagePath = packagePath + "/" + subPackagePath;
                }
                String subPackageName = fileName;
                if(StringUtil.isNotEmpty( packageName )){
                    subPackageName = packageName + "." + subPackageName;
                }
                addClass(classSet, subPackagePath, subPackageName);
            }
        }
    }

    private static void doAddClass(Set<Class<?>> classSet, String className){
        Class<?> cls = loadClass(className, false);
        classSet.add(cls);
    }





}
